In recent years, portable navigation devices (e.g., GPS devices) have become commonplace. GPS technology has now been miniaturized to the point where multi-purpose handheld computing devices (e.g., smart phones) now commonly include GPS receivers. When combined with mapping and route navigation software, these devices provide a convenient way for users to get directions and plan routes. However, such devices are still too large and difficult to handle for many navigation scenarios, such as when the user is running, riding a bicycle, or navigating difficult terrain. In such scenarios, it may be inconvenient or even dangerous to handle and interact with a smart phone in order to check a map or assess progress along an intended route.